And I'm Audie Cornish. Kids in Chicago are back in school. While teachers and school officials still need to iron out wrinkles in their new contract, both are satisfied they can do that with school in session. Chicago students lost seven days as a result of the strike.

Though parents are relieved schools are open again, NPR's Claudio Sanchez reports that some are worried about what they call the toxic climate that led to the strike and that lingers still.

UNIDENTIFIED MAN: What do we want?

UNIDENTIFIED GROUP: Fair contracts.

UNIDENTIFIED MAN: What do we want?

UNIDENTIFIED GROUP: Now.

CLAUDIO SANCHEZ, BYLINE: Angry teachers' demonstrations in Chicago have given way to recess and children playing in the cool September air.

UNIDENTIFIED CHILD: (Unintelligible)

SANCHEZ: But there was something else in the air this morning, a deep, lingering concern among parents. Cara Rudolph has two children at Helen C. Peirce Elementary. She says she's not sure if kids won anything as a result of the strike.

CARA RUDOLPH: It's like too soon to know what the good is that came out of it. A lot of questions come up, like, how are we going to make up the days that we lost? Will we make up the days that we lost? Will our school year stay longer or shorter if we've gained days or lost days with this new contract?

SANCHEZ: Parents have lots of questions: Will new teacher evaluations really help weed out bad teachers? Where will the money to pay teachers more come from if the school budget is almost a billion dollars in the red? And perhaps the biggest question of all, will the union and Mayor Rahm Emanuel be able to work together after all the vitriol? Kate Flynn has first grader at Peirce Elementary.

KATE FLYNN: I'm concerned about the level of toxicity that we all got to see between the Board of Education and the teachers' union. I don't know how that gets fixed. And part of my pipe dream would be that parents would rise up into that vacuum. But I don't - I honestly don't think that's going to happen.

SANCHEZ: Not if you consider that the deep, deep problems that have plagued public education in Chicago persist: child poverty, insufficient investment in kids. Then there's the issue of transparency, like on the huge issue of school closings that everybody knows are inevitable. Parents are totally in the dark about that, says Flynn.

FLYNN: Parents in Chicago don't really have a voice. And I don't really know why that is.

SANCHEZ: For Cara Rudolph, the lack of parental involvement simply boils down to fatigue. She says people in Chicago are tired of the conflict, of the finger-pointing and a history of unfulfilled promises that the quality of public education in Chicago will improve.

RUDOLPH: I feel like its been talked about for so long. It just was sad. It was so sad to see that we had to have this strike when we've had so much time. We've had a lot of time.

SANCHEZ: Teachers at Pierce Elementary say these are all legitimate concerns. Some say they, too, feel somewhat in the dark because so much of the contract that they'll be able to vote on in the next two weeks is still being written. No one knows, for example, if the issue of class size is even on the table anymore. And that's a key issue for kindergarten teacher Ted Wanberg, a 20-year veteran who was chosen as strike captain at Peirce Elementary.

On the bright side, says Wanberg, is that teachers in Chicago have never felt more unified, thanks to Mayor Rahm Emanuel.

TED WANBERG: Because I don't think there's any way that teachers could have been galvanized the way that it has been done through shared adversity.

SANCHEZ: Mayor Emanuel, for his part, in an emotional address Tuesday night, struck a note of reconciliation.

MAYOR RAHM EMANUEL: I want to thank parents and taxpayers for their patience. We showed that we are not just a city of big shoulders. We are a city of big hearts.

SANCHEZ: So now, with the strike out of the way, there is a small window, an opportunity for the mayor and the teachers' union to come together, to tackle the tough decisions about the big problems ahead, like the city's 40 percent dropout rate and growing number of kids who can barely read. What neither side is saying, though, is just how much they'll be willing to concede to make sure that these problems get solved. Claudio Sanchez, NPR News, Chicago. Transcript provided by NPR, Copyright National Public Radio.